Mounting for incandescent lamps



April 15, 1930. J, BERGMANS ET AL 1,755,096

MOUNTING FOR INCANDESCENT LAMPS Filed April 9, 1927 lnVenbors I Jan BG'PQmau15,

U|Jr e Nicolaas deWit,

Th ei r Att m'wey.

Patented Apr. 15, 1930 UNITED. STATES PATENT OFFICE JAIN BERGMANS .AIWD ULIBE NICOLAAS DE WIT, OF EINDHOVEN, NETHERLANDS,

' ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK MOUNTING FOR INCANDESCENT LAMPS Application filed April 9, 1927, Set al No. 182,471, and in the Netherlands May 22, 1926.

The invention relates to mountings for electric incandescent lamps, and-the principal object of the invention is to provide mountings for electric incandescent lamps such that the filament of the mounted lamp assumes a certain definite predetermined position in space. n

It has heretofore been proposed to make the base of a lamp in two parts, one a cylindrical shell to go into a socket, and the other somewhat spherical in shape and fastened to the bulb. The spherical part, after hav-.

ing been brought into the desired position in the cylindrical shell, is then soldered to it.

In accordance with this invention, a tubular holder or socket, preferably in the form of a clamp, which contains a base support, defined by three or more fixed points, such as inwardly projecting lugs, is provided for receiving a base fastened to the lamp, and of such shape that it may move freely inside the holder, and be brought into its correct position by means of said lugs or base support. In orderto permit the lamp base to move freely in the holder that part of it which is located inside the clamping holdermay be spherical, while the holder itself has a cylindrical bore. Further, the lamp base may be constructed with three or more grooves or notches distributed asymmetrically on its circumference or rim to operate in conjunction with the inwardly projecting lugs or pins in the holder to fix the lamp in a predetermined angular relation to the holder. The clamping force exerted on the lamp 'base in the holder may be varied, as for instance, by a clamping screw. The holder may be made in such a way that it can also be used for lamps which are equipped with a screw base. I The mounting made in accordance with the invention is of especial importance for projection service; in case the holder is used for a projector lamp, the holder may be fastened to the support of the reflector, which may be adjustable, and in this case, which is the usual one, the points of support in the holder may be located in any desired position. However, if the mirror isnot adjustable, the focal 50 point of the mirror is definitely positioned with reference to the points of support, and the filament of the lamp is adjusted to have a certam definite position'with reference to the center of curvature of the spherical surface of the lamp base, this adjustment being made by optical means so that the distance from the filament to a point of reference on the base, such as the lower edge of the base, 1s the same'for each lamp of the same kind. If a lamp equipped with this spherical base 1s placed n the clamp shaped holder, the filament w1ll be definitely located in space, provided the lower edge of the lamp base coincldes with the surface defined by the three polnts of support, or in other words, provided the lower edge of the base rests upon the three lnwardly projecting lugs or fixed points of support in the holder. If the lamp 1s replaced by another of the same type, then the filament of this latter lamp, if mounted correctly, will be the same distance from the pomts of support as the filament of the first lamp. In'order to be sure that the filament w1ll also assume a certain definite position in space, the lamp base, may be provided with three or more grooves or notches distributed asymmetrically on the base to cooperate with the points of support of the holder and there'- by fix the angular position of the lamp.

The invention will be explained more in detail by reference to the accompan ing drawing showing one example of an em odiment of the invention, and in which Fig. 1 is a view, partly in longitudinal section of a complete mounting with both the tubular clamping holder and the partly spherical base, and Fig. 2 is a top view of the clamping holder.

In the drawing 1 is a lamp base and 2 is a clamping lamp holder, both best shown in Fig. 1. The force to be exerted on the base bythe holder can be varied by a clamping screw 11 with a turn button 5. The points of support for the base are provided by lugs or pins 9 projecting inwardly into the bore of the holder to provide supports on which the lower edge of the base rests. I 7 is a lead a contact post 8 supplies the currentto the center contact of the lamp base. In the latter case the bottom edge of the threaded shell of the base rests upon the support lugs or pins 9, with the center contact of the base touching the contact post 8.

Fig. 2 shows the clamping holder, in which the force of clamping is adjusted by means of a clamping screw 11 with a turn button 5 of insulating material. An extension or arm 10 of the holder may be fastened to the supporting structure of a reflector such as 1s customarily used in projector mstallations.

A convenient way to provide the asymmetrically distributed grooves tor fixing the angular position of the lamp in the holder is to place the lugs or pins 9 asymmetrically on the holder, as appears from'Fig. 2, and provide the edge of the base shell 1 with correspondingly placed grooves or recesses 12, as shown in Fig. 1, to receive the pins 9 when the lamp is in place in the holder.

What we claim as new and desire to secure by Letters Patent of the United States is 1. In a mounting for incandescent lamps, the combination of a tubular holder with a base support having asymmetrically mounted members projecting inwardly into the bore of said holder, and a lamp base to be placed in said holder having a spherical portion which fits loosely into the bore of said holder and asymmetrical portions to fit said members.

2. In a mounting for incandescent lamps the combination of a tubular holder with base supporting pins projecting inwardly into the bore of said holder and positioned asymmetrically, and a lamp base having a spherical portion which fits loosely in the bore of said holder and a rim having in it notches which fit over said base supporting pins and are asymmetrically disposed on the rim of said base to correspond to said base supporting pins.

3. Ina mounting for electric incandescent lamps the combination of a tubular holder having a base support with a plurality of inwardly projecting pins fixed in asymmetrical relation to one another, and a lamp base to be placed in said holder and shaped to tilt treely in the holder and provided with pin engagmg recesses positioned to engage said pins when the lamp is correctly positioned in said holder.

4. In a mounting for electric incandescent lamps the combination of a tubular holder having a base support with a plurality of inwardly projecting lugs disposed asymmetrically about the axis of said holder, and a lamp base larger than the space between the 5. In a mounting for electric incandescent lamps the combination of a tubular holder constituting a clamp and having a base support with a plurality of inwardly projecting lugs disposed asymmetrically about the axis of said holder, and a lamp base having a spherical portion larger than the space between the inner ends of said lugs but smaller than the bore of said holder and having on its edge asymmetrically disposed notches which fit snugly over said lugs when said base is in position in said holder.

6. In a mounting for electric incandescent lamps the combination of a tubular holder having a base support with a plurality of projections asymmetrically projecting into the bore of said holder, and a lamp base having asymmetrically positioned recesses formed in its edge to extend longitudinally of said base and to fit snugly over said projections on said base support when said lamp base is in place in the holder.

In witness whereof, we have hereunto set our hands this 24th day of March, 1927.

JAN BERGMANS. ULBE NICOLAAS DE WIT. 

